Characteristics of patients in the derivation cohort and in the 3 cohorts for external validation of the HOMR score
| Characteristic* | Cohort; no. (%) of patients† | |||
|---|---|---|---|---|
| Derivation (1) (Ontario 2011) n = 640 022 | Ontario (2003–2010) n = 2 862 996 | Alberta (2011–2012) n = 210 595 | Boston (2010–2012) n = 66 683 | |
| Age, yr, median (IQR) | 59 (37 to 75) | 54 (35 to 72) | 51 (32 to 70) | 57 (45 to 69) |
| Male sex | 244 273 (38.2) | 1 074 241 (37.5) | 77 933 (37.0) | 29 426 (44.1) |
| Living status before admission | ||||
| Home, independent living | 531 017 (83.0) | 2 689 908 (94.0) | 202 949 (96.4) | 66 000 (99.0) |
| Rehabilitation facility | 1 113 (0.2) | 1 029 (0.04) | –§ | 473 (0.7) |
| Home, with home care | 77 589 (12.1) | 109 328 (3.8) | 7 713 (3.7) | –§ |
| Nursing home | 28 628 (4.5) | 60 080 (2.1) | 2 103 (1.0) | 210 (0.3) |
| Chronic care hospital | 1 675 (0.3) | 2 651 (0.1) | 181 (0.1) | –§ |
| Charlson Comorbidity Index score | ||||
| 0 | 369 844 (57.8) | 1 912 524 (66.8) | 129 539 (61.5) | 24 554 (36.8) |
| 1–2 | 138 987 (21.7) | 574 476 (20.1) | 44 023 (20.9) | 20 836 (31.2) |
| ≥ 3 | 131 191 (20.5) | 375 996 (13.1) | 39 384 (18.7) | 21 293 (31.9) |
| Home oxygen | 15 018 (2.3) | 19 235 (0.7) | –§ | 1 702 (2.6) |
| ≥ 1 visit to emergency department in past 12 mo | 287 678 (44.9) | 1 293 810 (45.2) | 71 678 (34.0) | 32 873 (49.3) |
| ≥ 1 admission to hospital by ambulance in past 12 mo | 60 339 (9.4) | 151 452 (5.3) | 22 522 (10.7) | 22 522 (33.8) |
| Admitting service — medicine | ||||
| General | 200 726 (31.4) | 769 804 (26.9) | 76 821 (36.5) | 23 094 (34.6) |
| Cardiology | 40 720 (6.4) | 188 947 (6.6) | 5 387 (2.6) | 6 538 (9.8) |
| Gastroenterology/nephrology/neurology | 31 454 (4.9) | 127 020 (4.4) | 4 589 (2.2) | 2 076 (3.1) |
| Palliative care | 4 999 (0.8) | 6 348 (0.2) | 1 372 (0.7) | –§ |
| Hematology/oncology | 15 031 (2.3) | 62 483 (2.2) | 1 293 (0.6) | 5 730 (8.6) |
| Admitting service — surgery | ||||
| General | 70 486 (11.0) | 344 679 (12.0) | 37 886 (18.0) | 5 490 (8.2) |
| Cardiovascular | 12 191 (1.9) | 54 853 (1.9) | 1 441 (0.7) | 6 766 (10.1) |
| Neurosurgery | 7 667 (1.2) | 36 922 (1.3) | 1 519 (0.7) | 2 405 (3.6) |
| Orthopedic | 53 865 (8.4) | 252 299 (8.8) | 12 850 (6.1) | 5 921 (8.9) |
| Plastic | 13 646 (2.1) | 77 055 (2.7) | 4 355 (2.1) | 1 430 (2.1) |
| Thoracic/transplant | 4 006 (0.6) | 12 808 (0.4) | 713 (0.3) | 258 (0.4) |
| Trauma | 8 573 (1.3) | 43 268 (1.5) | 2 645 (1.3) | 960 (1.4) |
| Urology | 20 997 (3.3) | 99 571 (3.5) | 4 331 (2.1) | 1 959 (2.9) |
| Obstetrics/gynecology | ||||
| Ante-, intra-, postpartum | 131 639 (20.6) | 634 971 (22.2) | 50 045 (23.8) | 29 (0.04) |
| Gynecology | 24 022 (3.8) | 151 879 (5.3) | 5 348 (2.5) | 4 027 (6.0) |
| Admission urgency | ||||
| Elective | 303 145 (47.4) | 1 485 392 (51.9) | 85 232 (40.5) | 32 042 (48.1) |
| Emergency department, no ambulance | 164 619 (25.7) | 787 321 (27.5) | 69 289 (32.9) | 28 068 (42.1) |
| Emergency department, ambulance | 172 258 (26.9) | 590 283 (20.6) | 56 074 (26.6) | 6 555 (9.8) |
| Urgent readmission (≤ 30 d of previous admission) | 29 128 (4.6) | 50 921 (1.8) | 11 979 (5.7) | 5 061 (7.6) |
| Admitted to intensive care unit | 47 637 (7.4) | 209 175 (7.3) | 14 525 (6.9) | 2 771 (4.2) |
| Diagnostic Risk Score,‡ mean ± SD | −1.79 ± 4.42 | −1.99 ± 4.52 | −1.44 ± 3.70 | −1.42 ± 3.72 |
Note: Boston = Brigham and Women’s Hospital, HOMR = Hospital-patient One-year Mortality Risk, IQR = interquartile rage, SD = standard deviation.
↵* Further details about the characteristics and the database sources are given in Appendix 2.
↵† Unless stated otherwise.
↵‡ Details about the Diagnostic Risk Score are given in Appendix 1. In the validation cohort, the Diagnostic Risk Score ranged from −22 to 12 (median 0, interquartile range −3 to 0).
↵§ Data unavailable in the administrative datasets.